<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	</head>
	<body>
	</body>
	<script type="text/javascript">
		var obj={
			name:"snw",
			age:18,
			sex:"man"
		}
		var result =Object.getOwnPropertyDescriptor(obj,"age");
		console.log(result);
		
		Object.preventExtensions(obj);
		
//		obj.zs=0;
//		console.log(obj.zs);
		
		
		Object.defineProperty(obj,"age",{
			value:30
		})
		console.log(obj.age);
		
		var result =Object.getOwnPropertyDescriptor(obj,"age");
		console.log(result);
	</script>
</html>
